Track submissions carefully.

Here are three common errors that the editors of a publication will not appreciate:

Your submitting to multiple publications when they want exclusive first printing rights.

Your submitting the same poem to them twice in one submission period or submitting more than the requested number of poems within the period.

Your pulling a submission from them because it has been accepted elsewhere when they only accept exclusive (not simultaneous) submissions.

Keeping close track of your submissions will help keep editors happy, and happy editors are more likely to publish your work. There is more information about tracking submissions and publications in Appendix
A.